Fix Resend contact sync payload and support separate contacts key

server.js

@@ -122,9 +122,10 @@ app.post('/api/contact', contactRateLimit, async (req, res) => {
 
     const resend = new Resend(process.env.RESEND_API_KEY)
     const { firstName, lastName } = splitName(trimmedName)
+    const contactResend = new Resend(process.env.RESEND_CONTACTS_API_KEY ?? process.env.RESEND_API_KEY)
 
     try {
-      const { error: contactError } = await resend.contacts.create({
+      const { error: contactError } = await contactResend.contacts.create({
         email: trimmedEmail,
         firstName,
         lastName,
@@ -132,22 +133,14 @@ app.post('/api/contact', contactRateLimit, async (req, res) => {
         ...(process.env.RESEND_SEGMENT_ID
           ? { segments: [{ id: process.env.RESEND_SEGMENT_ID }] }
           : {}),
-        properties: {
-          source: 'website-contact-form',
-          last_message_at: new Date().toISOString(),
-        },
       })
 
       if (contactError) {
-        const { error: updateError } = await resend.contacts.update({
+        const { error: updateError } = await contactResend.contacts.update({
           email: trimmedEmail,
           firstName,
           lastName,
           unsubscribed: false,
-          properties: {
-            source: 'website-contact-form',
-            last_message_at: new Date().toISOString(),
-          },
         })
 
         if (updateError) {